Merge branch 'master' into add-doctests-game-of-life

Author: cclauss

.devcontainer/devcontainer.json

@@ -1,17 +1,25 @@
 {
 	"name": "Python 3",
-	"build": {
-		"dockerfile": "Dockerfile",
-		"context": "..",
-		"args": {
-			// Update 'VARIANT' to pick a Python version: 3, 3.11, 3.10, 3.9, 3.8
-			// Append -bullseye or -buster to pin to an OS version.
-			// Use -bullseye variants on local on arm64/Apple Silicon.
-			"VARIANT": "3.13-bookworm"
-		}
-	},
 
-	"postCreateCommand": "zsh .devcontainer/post_install",
+	// Use a prebuilt dev container image instead of building from a local
+	// Dockerfile. The repo migrated its dependencies to pyproject.toml, so the
+	// old Dockerfile's `COPY requirements.txt` step no longer had a file to copy
+	// and the image build failed. The upstream images already ship Python + a
+	// full toolchain, so pulling one is both faster and less to maintain.
+	//
+	// This repo tracks the latest-and-greatest CPython on the newest stable
+	// Debian. Images are published per CPython minor version on Debian 13
+	// "Trixie" (3.11-trixie ... 3.14-trixie); bump this to the newest available
+	// when a new stable CPython ships.
+	// NOTE: these images do not publish free-threaded (`t`) variants, so 3.14t
+	// cannot be selected via the tag alone -- but the repo's `.python-version`
+	// pins 3.14t, and `uv run`/`uv sync` in the container honor it, so uv gives
+	// contributors free-threaded 3.14t regardless of the base tag.
+	"image": "mcr.microsoft.com/devcontainers/python:latest",
+
+	// Install the tools post_install and CI expect (pre-commit + ruff), plus uv
+	// for the free-threaded workflow above, then run the existing setup script.
+	"postCreateCommand": "pipx install pre-commit ruff uv && zsh .devcontainer/post_install",
 
 	// Configure tool-specific properties.
 	"customizations": {
@@ -20,26 +28,30 @@
 			// Set *default* container specific settings.json values on container create.
 			"settings": {
 				"python.defaultInterpreterPath": "/usr/local/bin/python",
-				"python.linting.enabled": true,
-				"python.formatting.blackPath": "/usr/local/py-utils/bin/black",
-				"python.linting.mypyPath": "/usr/local/py-utils/bin/mypy",
+				// Formatting/linting is handled by Ruff (matches pre-commit and CI).
+				"editor.formatOnSave": true,
+				"[python]": {
+					"editor.defaultFormatter": "charliermarsh.ruff",
+					"editor.codeActionsOnSave": {
+						"source.fixAll": "explicit",
+						"source.organizeImports": "explicit"
+					}
+				},
 				"terminal.integrated.defaultProfile.linux": "zsh"
 			},
 
 			// Add the IDs of extensions you want installed when the container is created.
 			"extensions": [
 				"ms-python.python",
-				"ms-python.vscode-pylance"
+				"ms-python.vscode-pylance",
+				"charliermarsh.ruff"
 			]
 		}
 	},
 
 	// Use 'forwardPorts' to make a list of ports inside the container available locally.
 	// "forwardPorts": [],
 
-	// Use 'postCreateCommand' to run commands after the container is created.
-	// "postCreateCommand": "pip3 install --user -r requirements.txt",
-
 	// Comment out to connect as root instead. More info: https://aka.ms/vscode-remote/containers/non-root.
 	"remoteUser": "vscode"
 }

.github/skills/code-review/SKILL.md

@@ -0,0 +1,69 @@
+# Skill: Code review for TheAlgorithms/Python
+
+Review a pull request against the rules already written in
+[`CONTRIBUTING.md`](../../../CONTRIBUTING.md). The goal is a review that any
+reviewer (human or AI) can run the same way every time, and that produces a clear,
+kind, actionable verdict.
+
+## How to run this skill
+
+Read the PR diff, then work through the four `CONTRIBUTING.md` sections in order
+and emit the fixed output shape below. Cite the exact rule you are applying and
+suggest the fix — never just "rejected".
+
+### 1. Before contributing / Is this an algorithm?
+
+- [ ] The change adds, fixes, or documents **one algorithm** — not multiple, and
+      not both code and doctest changes in the same PR.
+- [ ] It is a genuine algorithm or data structure (see the *What is an Algorithm?*
+      section), not a script, snippet, how-to-use for an existing API, or exercise
+      dump.
+- [ ] It is **not already in the repository** (search the existing directories).
+- [ ] **No earlier open PR** already does the same thing — link it if one exists.
+- [ ] Properly attributed — no plagiarism; prior sources credited.
+
+### 2. Coding Style
+
+- [ ] `from __future__ import annotations` is not needed because this repo only uses
+      the latest version of CPython.
+- [ ] File and directory names are lowercase, use underscores, and land inside an
+      existing directory.
+- [ ] Public functions/classes have **type hints**.
+- [ ] Public functions have **doctests that actually pass**.
+- [ ] Descriptive variable and function names (no single letters where a word helps).
+- [ ] Code is formatted and lint-clean (`ruff`, `pre-commit`).
+
+### 3. Other Requirements for Submissions
+
+- [ ] At least one **Wikipedia (or equivalent) URL** documenting the algorithm.
+- [ ] Docstring explains what the function does and its parameters/returns.
+- [ ] No unnecessary third-party dependencies.
+
+### 4. Verdict — fixed output shape
+
+Emit exactly these headings so reviews are comparable and easy to automate:
+
+```
+### Is this an algorithm? — <yes/no + one-line why>
+### Duplicate / prior-art check — <#NNNN | none found>
+### Coding style — <pass | issues: …>
+### Other requirements (doctests, type hints, descriptive names, Wikipedia URL) — <pass | issues: …>
+### Verdict — <approve | request changes | close> + one-line reason
+```
+
+## Tone
+
+Be specific and kind. Point at the exact `CONTRIBUTING.md` rule and offer the fix
+rather than a bare rejection — first-time and Hacktoberfest contributors are more
+likely to come back and improve the PR when the path forward is clear.
+
+## Map findings to labels
+
+Where a finding matches an existing label, name it so the review lines up with the
+maintenance/cleanup tooling:
+
+- missing/failing doctests → `require tests`
+- missing type hints → `require type hints`
+- non-descriptive names → `require descriptive names`
+- CI red → `tests are failing`
+- otherwise ready for a maintainer → `awaiting reviews`

.github/workflows/build.yml

@@ -9,20 +9,36 @@ jobs:
   build:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5
-      - uses: astral-sh/setup-uv@v6
+      - uses: actions/checkout@v7
+      - uses: astral-sh/setup-uv@v7
         with:
           enable-cache: true
           cache-dependency-glob: uv.lock
-      - uses: actions/setup-python@v6
+      - uses: actions/setup-python@v7
         with:
-          python-version: 3.x
+          python-version-file: .python-version
           allow-prereleases: true
       - run: uv sync --group=test
       - name: Run tests
-        # TODO: #8818 Re-enable quantum tests
-        run: uv run pytest
+        # opencv-python is gated out on 3.14t (no cp314t wheel yet), so skip the
+        # files that import cv2. Pure-Python algorithms in computer_vision/ and
+        # data_compression/ still run; digital_image_processing/ is almost entirely
+        # cv2-based so it is skipped as a tree. Re-enable when a cp314t wheel ships.
+        # --ignore-gil-enabled: some compiled deps (sklearn, xgboost, ...) don't
+        # yet ship the Py_mod_gil slot, so importing them re-enables the GIL under
+        # 3.14t. That's an upstream-wheel gap, not our code; the flag lets the suite
+        # run anyway and pytest-run-parallel still reports which tests are not
+        # thread-safe. Drop the flag once the scientific stack ships free-threaded wheels.
+        # qiskit is likewise gated out of the 3.14t deps (Qiskit/qiskit#16893), so the
+        # single file that imports it (quantum/q_fourier_transform.py) is skipped too.
+        run: uv run --with=pytest-run-parallel pytest
+          --iterations=8 --parallel-threads=auto --ignore-gil-enabled
           --ignore=computer_vision/cnn_classification.py
+          --ignore=computer_vision/flip_augmentation.py
+          --ignore=computer_vision/harris_corner.py
+          --ignore=computer_vision/mosaic_augmentation.py
+          --ignore=data_compression/peak_signal_to_noise_ratio.py
+          --ignore=digital_image_processing/
           --ignore=docs/conf.py
           --ignore=dynamic_programming/k_means_clustering_tensorflow.py
           --ignore=machine_learning/lstm/lstm_prediction.py

.github/workflows/devcontainer_ci.yml

@@ -4,15 +4,17 @@ on:
   push:
     paths:
       - ".devcontainer/**"
+      - ".github/workflows/devcontainer_ci.yml"
   pull_request:
     paths:
       - ".devcontainer/**"
+      - ".github/workflows/devcontainer_ci.yml"
 
 jobs:
   build:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v7
       - uses: devcontainers/ci@v0.3
         with:
           push: never

.github/workflows/directory_writer.yml

@@ -6,12 +6,13 @@ jobs:
   directory_writer:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v7
         with:
           fetch-depth: 0
-      - uses: actions/setup-python@v6
+      - uses: actions/setup-python@v7
         with:
-          python-version: 3.x
+          python-version-file: .python-version
+          allow-prereleases: true
       - name: Write DIRECTORY.md
         run: |
           scripts/build_directory_md.py 2>&1 | tee DIRECTORY.md

.github/workflows/project_euler.yml

@@ -14,21 +14,23 @@ jobs:
   project-euler:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5
-      - uses: astral-sh/setup-uv@v6
-      - uses: actions/setup-python@v6
+      - uses: actions/checkout@v7
+      - uses: astral-sh/setup-uv@v7
+      - uses: actions/setup-python@v7
         with:
-          python-version: 3.x
+          python-version-file: .python-version
+          allow-prereleases: true
       - run: uv sync --group=euler-validate --group=test
       - run: uv run pytest --doctest-modules --cov-report=term-missing:skip-covered --cov=project_euler/ project_euler/
   validate-solutions:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5
-      - uses: astral-sh/setup-uv@v6
-      - uses: actions/setup-python@v6
+      - uses: actions/checkout@v7
+      - uses: astral-sh/setup-uv@v7
+      - uses: actions/setup-python@v7
         with:
-          python-version: 3.x
+          python-version-file: .python-version
+          allow-prereleases: true
       - run: uv sync --group=euler-validate --group=test
       - run: uv run pytest scripts/validate_solutions.py
         env:

.github/workflows/ruff.yml

@@ -11,6 +11,6 @@ jobs:
   ruff:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5
-      - uses: astral-sh/setup-uv@v6
+      - uses: actions/checkout@v7
+      - uses: astral-sh/setup-uv@v7
       - run: uvx ruff check --output-format=github .

.github/workflows/sphinx.yml

@@ -25,16 +25,16 @@ jobs:
   build_docs:
     runs-on: ubuntu-24.04-arm
     steps:
-      - uses: actions/checkout@v5
-      - uses: astral-sh/setup-uv@v6
-      - uses: actions/setup-python@v6
+      - uses: actions/checkout@v7
+      - uses: astral-sh/setup-uv@v7
+      - uses: actions/setup-python@v7
         with:
-          python-version: 3.13
+          python-version-file: .python-version
           allow-prereleases: true
       - run: uv sync --group=docs
-      - uses: actions/configure-pages@v5
+      - uses: actions/configure-pages@v6
       - run: uv run sphinx-build -c docs . docs/_build/html
-      - uses: actions/upload-pages-artifact@v4
+      - uses: actions/upload-pages-artifact@v5
         with:
           path: docs/_build/html
 
@@ -46,5 +46,5 @@ jobs:
     needs: build_docs
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/deploy-pages@v4
+      - uses: actions/deploy-pages@v5
         id: deployment

.github/workflows/ty.yml

@@ -0,0 +1,51 @@
+# https://docs.astral.sh/ty/
+name: ty
+on:
+  push:
+    branches:
+      - master
+  pull_request:
+    branches:
+      - master
+jobs:
+  ty:
+    runs-on: ubuntu-latest
+    # Informational only: ty is not yet a required gate. This job surfaces
+    # type-check findings in the logs so they can be triaged into gradual
+    # [tool.ty] rules without blocking merges. Flip `continue-on-error` to
+    # false once the baseline is clean.
+    continue-on-error: true
+    steps:
+      - uses: actions/checkout@v7
+      - uses: astral-sh/setup-uv@v7
+        with:
+          enable-cache: true
+          cache-dependency-glob: uv.lock
+      # Mirror the `build` job: `uv sync` installs the dependencies without
+      # building this flat-layout repo as a wheel. pyproject.toml has no
+      # [build-system], so uv treats the project as virtual and installs only
+      # its dependencies -- no "Multiple top-level packages discovered in a
+      # flat-layout" error and no need for a src-layout. (`uv pip install .`
+      # would force that wheel build and fail.) Pin a regular GIL 3.14 so typed
+      # third-party dependencies resolve; the free-threaded 3.14t interpreter the
+      # test matrix uses lacks wheels for several of them. ty itself is pulled in
+      # ephemerally with `--with` so it needn't be added to the lockfile.
+      - run: uv sync --python 3.14
+      # Pin the *run* to the same regular-GIL 3.14 too. Without `--python 3.14`
+      # here, `uv run` re-resolved the project's default interpreter -- the
+      # free-threaded 3.14t used by the test matrix -- so ty type-checked against
+      # an env where many third-party stubs don't resolve, drowning real findings
+      # in `unresolved-import` / `unresolved-attribute` noise. Pinning 3.14 lets
+      # ty see the synced dependencies, so the `[tool.ty.rules]` severities in
+      # pyproject.toml apply to a meaningful baseline.
+      #
+      # `--exit-zero` is ty's native advisory switch (the analog of ruff's
+      # `ruff check --exit-zero`): the step always exits 0, yet with
+      # `--output-format=github` ty still emits ::error annotations that render
+      # inline on the diff, so findings stay visible without a red X. Promotion
+      # path: `--exit-zero` (informational, always green) -> `--exit-zero-on-warning`
+      # (fail only on error-severity, tolerate warnings) -> drop the flag entirely
+      # to make ty a required gate once the [tool.ty] baseline is clean.
+      # `continue-on-error: true` above stays as a belt-and-suspenders guard so a
+      # ty *crash* (not a diagnostic) can never block a merge either.
+      - run: uv run --python 3.14 --with ty ty check --output-format=github --exit-zero

.gitignore

@@ -73,7 +73,6 @@ target/
 .ipynb_checkpoints
 
 # pyenv
-.python-version
 
 # celery beat schedule file
 celerybeat-schedule